1. Field of the Invention
The present invention relates to an image display apparatus for displaying a series of images picked up inside a subject along time series.
2. Description of the Related Art
In the field of endoscope, swallowable capsule endoscopes equipped with an imaging function and a radio communication function have been proposed and intra-subject information acquisition systems which acquire images inside a subject using such capsule endoscopes have been developed. After being swallowed through the mouth of a subject for observation (examination), a capsule endoscope moves through organs such as stomach and small intestine in accordance with peristaltic movement thereof before being naturally excreted from the subject and sequentially picks up images inside the subject at intervals of, for example 0.5 sec.
While the capsule endoscope moves inside the subject, images picked up by the capsule endoscope are sequentially transmitted to an external receiving apparatus by radio communication. The receiving apparatus has a radio communication function and a memory function and sequentially saves images received from the capsule endoscope inside the subject in a memory. By carrying such a receiving apparatus, the subject can act freely between the time when the subject swallows the capsule endoscope and the time when the capsule endoscope is naturally excreted. After the capsule endoscope is naturally excreted from the subject, a physician or a nurse can diagnose the subject by making an image display apparatus take in images accumulated in the memory of the receiving apparatus and display images of organs inside the subject (See, for example, Japanese Patent Application Laid-Open No. 2003-19111).
In such an intra-subject information acquisition system, a multiple-lens capsule endoscope equipped with a plurality of imaging devices may be used. Such a multiple-lens capsule endoscope has the plurality of imaging devices imaging mutually different directions to acquire images from a plurality of directions picked up by the plurality of imaging devices (See, for example, US Patent Application Laid-Open No. 2002/0109774 Specification). In this case, the multiple-lens capsule endoscope transmits the acquired images from the plurality of directions to a receiving apparatus by radio. The receiving apparatus sequentially accumulates images from the plurality of directions picked up by the multiple-lens capsule endoscope. An image display apparatus takes in image groups from the plurality of directions accumulated in the receiving apparatus and displays each image contained in the acquired image groups alternately in each display area of a screen (See, for example, Japanese Patent Application Laid-open No. 2006-68534). Image display apparatuses that display a large quantity of images picked up by imaging devices in each display area of the screen separately include those disclosed in Japanese Patent Application Laid-Open No. 2002-211049 and Japanese Patent Application Laid-Open No. H11-259630.